Highly abrasion-resistant polyolefin pipe

ABSTRACT

A pipe- or tube-shaped article having an innermost layer is disclosed which comprises a polyolefin composition comprising a polyolefin comprising ethylene and an α-olefin. The article provides long lifetime, highly abrasion-resistant pipes for mining and other transportation uses. Also disclosed are methods for preparing the article and transporting abrasive materials.

This application claims priority to U.S. provisional application61/110,424, filed Oct. 31, 2008; the entire disclosure of which isincorporated herein by reference.

The invention relates to highly abrasion-resistant tubular articlescomprising polyolefin layers that provide for the transport ofparticulates and slurries, methods and compositions to produce thearticles, and methods of transporting abrasive materials through them.

BACKGROUND OF THE INVENTION

Mining operations require the transport of highly abrasive particulateor slurry streams. The recovery of bitumen from oil sands is becomingincreasingly important within the energy industry. Processing oil sandincludes transporting and conditioning the oil sand as an aqueous slurryover kilometer lengths of pipe up to 1 meter in diameter. Processes forthe recovery of bitumen from oil sands are known (U.S. Pat. Nos.4,255,433; 4,414,117; 4,512,956; 4,533,459; 5,039,227; 6,007,708;6,096,192; 6,110,359; 6,277,269; 6,391,190; 2006/0016760;US2006/0249431; US2007/0023323; US2007/0025896; WO2006/060917;CA1251146; CA2195604; CA2227667; CA2420034; CA2445645; and CA2520943).Use of caustic to assist in the recovery process of oil from oil sandsis also known (US2006/0016760 and US2006/0249431). Other miningoperations that include the transport of highly abrasive particulate orslurry streams from the mine to processing refinery include, forexample, iron ore, coal and coal dust, and the like, and in furthernon-mining transport processes, such as grain, sugar and the like.

Often, metal pipes, such as carbon steel or cast iron pipes, are usedfor the transport of these highly abrasive streams. They are expensive,heavy and only provide a temporary solution since they are eventuallydestroyed. To increase their lifetimes, the metal pipes may be rotated90 degrees on their axes on a regular basis to provide a new transportsurface. However, because of the pipe weight, this rotation is difficultand ultimately the entire pipe is worn out and must be replaced.

Use of plastic pipes, pipe liners and pipe coatings has been proposed toreduce these shortcomings. Material selection is critical. Many of thecommonly available materials cannot stand up to such highly-abrasivemining streams and are quickly worn out. For example, high densitypoly(ethylene) pipes are generally used as liners for sanitary sewer andwastewater pipelines but they rapidly degrade under highly abrasiveenvironments. U.S. Pat. No. 4,042,559 discloses abrasive granule-filled,partially-cured coatings for use in abrasion resistant coated pipes forthe transport of mining slurries. U.S. Pat. No. 4,254,165 disclosesprocesses to produce abrasion resistant pipes with 0.04-0.05-inch thickcoatings of filled (such as sand) polyolefins, such as low and mediumdensity poly(ethylene) and including poly(ethylene-co-acrylic acid).U.S. Pat. No. 4,339,506; WO90/10032 and CA1232553 disclose rubber linersfor pipes. U.S. Pat. No. 4,215,178 discloses fluoropolymer-modifiedrubber pipe liners. US2006/0137757 and US2007/0141285 disclosefluoropolymer pipe liners. Polyurethane pipe coatings are known (U.S.Pat. No. 3,862,921; U.S. Pat. No. 4,025,670; US2005/0194718;US2008/0174110; GB2028461; JP02189379; JP03155937; and JP60197770).US2005/0189028 discloses metal pipe coated with a polyurethane liner totransport tar sand slurry. GB2028461 discloses an abrasion-resistantpipe lining comprising a urethane rubber thermoset embedded with theparticles of the material to be transported (coal dust, grain or sugar)through transport of the materials during curing. Abrasion resistantpipes with elastomeric polyurea coatings are disclosed in U.S. Pat. No.6,737,134. A shortcoming of the polyurethane coatings includes thehighly complex processes for applying the coating to the metal pipe.

Use of polyolefin compositions made from polyolefin compositions aspipes, pipe liners and pipe coatings is known. For example, U.S. Pat.No. 4,481,239 discloses polyethylene powder coatings for pipes which mayinclude an adhesive layer comprising certain acid copolymer powdercoatings.

U.S. Pat. Nos. 3,932,368, 4,237,037, 4,345,004 and 4,910,046 disclosepolyolefin powder coatings for metal substrates which may include polargroup modified olefinic resins, such as carboxyl- or anhydride-modifiedresins. U.S. Pat. No. 5,211,990 disclose a flame spraying process ofpolyolefin powders onto metal substrates that include polyolefinsgrafted with acid or anhydride functionality and ethylene/(meth)acrylicacid copolymers and ionomers derived therefrom. U.S. Pat. No. 5,275,848discloses a powder coating process for metal substrates with polyolefinpowders that include polyolefins grafted with acid or anhydridefunctionality and ethylene/(meth)acrylic acid copolymers and ionomersderived therefrom. U.S. Pat. No. 5,677,377 and U.S. Pat. No. 5,677,378disclose corrosion-resistant powder coatings for steel plate whichinclude maleic anhydride-grafted polypropylene powder. U.S. Pat. No.5,976,652 discloses corrosion-resistant polypropylene film coatings forsteel containers adhered with carboxylic acid- or anhydride-functionalpolypropylenes.

A shortcoming of the art polyolefin pipes, pipe liners and pipe coatingsis low abrasion resistance resulting in short service lifetimes.

SUMMARY OF THE INVENTION

The invention is directed to a pipe- or tube-formed article having aninnermost layer wherein the innermost layer has a thickness of about0.001 to about 102 mm and comprises a polyolefin composition, thepolyolefin comprising ethylene and an α-olefin having 3 to 20 carbonshaving a density of about 0.92 g/cc (ASTM D-792) or less.

The invention is also directed to a method for producing apolyolefin-lined metal pipe comprising the step of pulling or insertinga pre-formed polyolefin pipe or multilayer polyolefin pipe into apreformed metal pipe.

The invention also provides a method to produce a polyolefin-lined metalpipe comprising the step of laying up a pre-formed polyolefin film orsheet or multilayer polyolefin film or sheet into a preformed metalpipe.

The invention also provides a method for transporting an abrasivematerial comprising obtaining a pipe- or tube-formed article asdescribed above; preparing an abrasive material composition suitable forpumping through the article; pumping the abrasive material compositioninto one end of the pipe- or tube-formed article and receiving theabrasive material composition out of the other end of pipe- ortube-formed article.

DETAILED DESCRIPTION OF THE INVENTION

All publications, patent applications, patents, and other referencesmentioned herein are incorporated by reference in their entirety. Unlessotherwise defined, all technical and scientific terms used herein havethe same meaning as commonly understood by one of ordinary skill in theart to which this invention belongs. In case of conflict, the presentspecification, including definitions, will control.

Except where expressly noted, trademarks are in upper case.

Although methods and materials similar or equivalent to those describedherein can be used in the practice or testing of the present invention,suitable methods and materials are described herein.

Unless stated otherwise, all percentages, parts, ratios, etc., are byweight. When an amount, concentration, or other value or parameter isgiven as either a range, preferred range or a list of upper preferablevalues and lower preferable values, this is to be understood asspecifically disclosing all ranges formed from any pair of any upperrange limit or preferred value and any lower range limit or preferredvalue, regardless of whether ranges are separately disclosed. Where arange of numerical values is recited herein, unless otherwise stated,the range is intended to include the endpoints thereof, and all integersand fractions within the range. It is not intended that the scope of theinvention be limited to the specific values recited when defining arange.

When the term “about” is used in describing a value or an end-point of arange, the disclosure should be understood to include the specific valueor end-point referred to.

As used herein, the terms “comprises,” “comprising,” “includes,”“including,” “containing,” “characterized by,” “has,” “having” or anyother variation thereof, are intended to cover a non-exclusiveinclusion. For example, a process, method, article, or apparatus thatcomprises a list of elements is not necessarily limited to only thoseelements but may include other elements not expressly listed or inherentto such process, method, article, or apparatus. Further, unlessexpressly stated to the contrary, “or” refers to an inclusive or and notto an exclusive or. For example, a condition A or B is satisfied by anyone of the following: A is true (or present) and B is false (or notpresent), A is false (or not present) and B is true (or present), andboth A and B are true (or present).

The transitional phrase “consisting of excludes any element, step, oringredient not specified in the claim, closing the claim to theinclusion of materials other than those recited except for impuritiesordinarily associated therewith. When the phrase “consists of appears ina clause of the body of a claim, rather than immediately following thepreamble, it limits only the element set forth in that clause; otherelements are not excluded from the claim as a whole.

The transitional phrase “consisting essentially of limits the scope of aclaim to the specified materials or steps and those that do notmaterially affect the basic and novel characteristic(s) of the claimedinvention. “A ‘consisting essentially of’ claim occupies a middle groundbetween closed claims that are written in a ‘consisting of’ format andfully open claims that are drafted in a ‘comprising’ format.”

Where applicants have defined an invention or a portion thereof with anopen-ended term such as “comprising,” it should be readily understoodthat (unless otherwise stated) the description should be interpreted toalso describe such an invention using the terms “consisting essentiallyof” or “consisting of”

Use of “a” or “an” are employed to describe elements and components ofthe invention. This is done merely for convenience and to give a generalsense of the invention. This description should be read to include oneor at least one and the singular also includes the plural unless it isobvious that it is meant otherwise.

In describing certain polymers it should be understood that sometimesapplicants are referring to the polymers by the monomers used to makethem or the amounts of the monomers used to make them. While such adescription may not include the specific nomenclature used to describethe final polymer or may not contain product-by-process terminology, anysuch reference to monomers and amounts should be interpreted to meanthat the polymer is made from those monomers or that amount of themonomers, and the corresponding polymers and compositions thereof.

The materials, methods, and examples herein are illustrative only and,except as specifically stated, are not intended to be limiting.

The polyolefin compositions and methods described herein may be used toprovide long lifetime, highly abrasion-resistant pipes for a widevariety of mining and other transportation uses in a wide range ofenvironmental conditions. High burst strength may be another attributeof the pipes.

Polyolefin Layer Composition

By thermoplastic polyolefin polymer, polyolefin and similar terms usedherein, reference is made to a thermoplastic polyolefin comprisingcopolymerized units of ethylene and an α-olefin having 3 to 20 carbonshaving a density of about 0.92 g/cc (ASTM D792) or less.

The polyolefin copolymer comprises ethylene and α-olefin comonomers. Itcomprises at least two monomers, but may incorporate more than twocomonomers, such as terpolymers, tetrapolymers and the like. Preferably,the polyolefin copolymer comprises from about 5 wt % to about 50 wt % ofthe α-olefin comonomer (based on the total weight of the polyolefincopolymer), more preferably about 15 wt % to about 45 wt %, yet morepreferably about 20 wt % to about 40 wt %, and most preferably, about 25wt % to about 35 wt %.

The α-olefin comonomer contains from 3 to 20 carbons and may be alinear, branched or cyclic α-olefin. Preferable α-olefins are selectedfrom the group consisting of propene, 1-butene, 3-methyl-1-butene,4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-dodecene,1-tetradecene, 1-hexadecene, 1-octadecene, 3-cyclohexyl-1-propene, vinylcyclohexane and the like and mixtures thereof. The α-olefin comonomerpreferably contains 3 to 10 carbons. The density of the α-olefincopolymer will generally depend on the type and level of α-olefinincorporated.

The polyolefin copolymer may optionally incorporate a minor amount ofother olefinic comonomers; for example cyclic olefins such asnorbornene; styrene; dienes such as dicyclopentadiene, ethylidenenorbornene and vinyl norbornene; and the like and mixtures thereof. Whenincluded, the optional comonomer may be incorporated at a level of about15 wt % or less, based on the total weight of the polyolefin copolymer.

The polyolefin does not include α,β-ethylenically unsaturated carboxylicacid or anhydride grafted to the parent polyolefin.

The polyolefin may be produced by any known method and may be catalyzedwith any known polymerization catalyst such as, for example, radical-,Ziegler-Natta- or metallocene-catalyzed polymerizations (e.g. U.S. Pat.Nos. 3,645,992; 5,026,798; 5,055,438; 5,057,475; 5,064,802; 5,096,867;5,132,380; 5,231,106; 5,272,236; 5,278,272; 5,374,696; 5,420,220;5,453,410; 5,470,993; 5,703,187; 5,986,028; 6,013,819; 6,159,608; andEP514828).

Preferably, the polyolefin has a density of about 0.90 g/cc or less,more preferably a density of about 0.88 g/cc or less, and mostpreferably a density of about 0.88 to about 0.84 g/cc. Blends of two ormore polyolefin copolymers may be used, if desired, as long as thedensity of the blend meets the requirements listed above for the singlepolyolefin copolymer.

The polyolefin may have Shore A hardness of about 96 or less (ASTMD2240, ISO 868). Preferably, the polyolefin has Shore A hardness ofabout 80 or less; more preferably, about 70 or less; most preferably,about 70 to about 50. The polyolefin may be blended with other polymericmaterials as long as the Shore A hardness of the blend conforms to theabove requirements.

The compositions may be used with additives known in the art. Theadditives include plasticizers, processing aids, flow enhancingadditives, flow reducing additives, lubricants, flame retardants, impactmodifiers, nucleating agents to increase crystallinity, antiblockingagents such as silica, thermal stabilizers, UV absorbers, UVstabilizers, dispersants, surfactants, chelating agents, couplingagents, adhesives, primers and the like. One of ordinary skill in theart will recognize that additives may be added to the polyolefincomposition using techniques known in the art or variants thereof, andwill know the proper amounts for addition based upon typical usage. Thetotal amount of additives used in the polyolefin composition may be upto about 15 weight % (based upon the weight of the polyolefincomposition).

The polyolefin compositions may contain additives that effectivelyreduce the melt flow of the resin, which may be present in any amountthat permits production of thermoset compositions. The use of suchadditives will enhance the upper end-use temperature and reduce creep ofthe pipes produced therefrom. The cured polyolefin compositions may haveenhanced resistance to the low molecular weight aromatic fraction andnaptha commonly contained in oil sand slurries.

Melt flow reducing additives include organic peroxides, such as2,5-dimethylhexane-2,5-dihydroperoxide,2,5-dimethyl-2,5-di(tert-butylperoxy)hexane-3, di-tert-butyl peroxide,tert-butylcumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane,dicumyl peroxide, α,α′-bis(tert-butyl-peroxyisopropyl)benzene,n-butyl-4,4-bis(tert-butylperoxy)valerate,2,2-bis(tert-butylperoxy)butane, 1,1-bis(tert-butyl-peroxy)cyclohexane,1,1-bis(tert-butylperoxy)-3,3,5-trimethyl-cyclohexane, tert-butylperoxybenzoate, benzoyl peroxide, and the like and mixtures combinationsthereof. Preferably the organic peroxides decompose at a temperature ofabout 100° C. or higher to generate radicals. More preferably, theorganic peroxides have a decomposition temperature that affords a halflife of 10 hours at about 70° C. or higher to provide improved stabilityfor blending operations. The organic peroxides may be added at a levelof about 0.01 to about 10 wt %, or about 0.5 to about 3 wt %, based onthe total weight of the grafted polyolefin composition.

If desired, initiators such as dibutyltin dilaurate may also be presentin the polyolefin composition at about 0.01 to about 0.05 wt %, based onthe total weight of the polyolefin composition. Also if desired,inhibitors such as hydroquinone, hydroquinone monomethyl ether,p-benzoquinone, and methylhydroquinone may be added for the purpose ofenhancing control to the reaction and stability. The inhibitors may beadded at a level of less than about 5 wt %, based on the total weight ofthe composition.

Alternative melt flow reducing additives include known peroxide-silanoladditives that often include a peroxide (as described above), a silaneand a catalyst. These additive systems provide moisture curablematerials. Such systems may be added in a concentrate form, such ascommercially available under the SILCAT trademark (Momentive PerformanceMaterials, Wilton, Conn., USA).

The polyolefin composition may further comprise about 0.1 to about 80weight % filler based on the total weight of the filled composition.

Preferably, the filler is abrasion-resistant filler. The filler may bereinforcing filler or non-reinforcing filler. Specific examples ofpreferred reinforcing fillers include high strength fibers such asfiberglass, continuous glass fiber, polyaramide fiber, KEVLAR (a productof E. I. du Pont de Nemours and Company (DuPont), Wilmington, Del.),graphite, carbon fiber, silica, quartz, ceramic, silicon carbide, boron,alumina, alumina-silica, polyethylene, ultrahigh molecular weightpolyethylene, polyimide, liquid crystal polymers, polypropylene,polyester, polyamide and the like. For example, US2006/0124188 andUS2006/0151042 disclose fiber-reinforced pipe liners. Specific examplesof non-reinforcing fillers include particles of abrasion-resistantminerals, marble, slate, granite, sand, potters' sand, silicates,limestone, clay, glass, quartz, metallic powders, aluminum powders,stainless steel powders, zinc metal, refractory metal borides (such asborides of aluminum, niobium, silicon, tantalum, titanium, tungsten, andzirconium), carbides (such as carbides of boron, niobium, silicon,tantalum, titanium, tungsten and zirconium), nitrides (such as nitridesof aluminum, boron, niobium, silicon, tantalum, titanium, tungsten andzirconium), oxides (such as oxides of aluminum, niobium, silicon,tantalum, titanium, tungsten and zirconium), silicon carbide, alumina,fused combinations of alumina and zirconia, calcium carbonate, bariumsulfate, magnesium silicate and the like and combinations thereof.

The size of the filler incorporated in the polyolefin compositiondepends on the thickness and diameter of the polyolefin pipe and shouldbe smaller than the thickness of the polyolefin pipe. Preferably, amixture of particle sizes is used to provide a higher density(percentage by volume) of filler incorporated. For abrasion-resistantfillers, this may result in a higher abrasion resistance of the filledpolyolefin pipe. Filled polymeric pipes are known (U.S. Pat. Nos.3,498,827; 4,042,559; 4,254,165; 4,407,893; 5,091,260; 5,562,989; and GB2028461).

Polyolefin Pipe

The article in the form of a pipe comprising the polyolefin compositioncomprises an innermost layer having a thickness of about 0.001 to about102 mm (about 0.00004 to about 4 inches) of the polyolefin composition.The pipe may have a hollow circular profile and the wall thickness maybe generally uniform around the circumference of the pipe. This shouldnot be taken as limiting. The pipe may have any profile and the wallthickness may vary around the circumference of the pipe as desired. Thepolyolefin composition is positioned as the innermost layer to providesuperior abrasion-resistance. The polyolefin pipe thickness provides notonly a long lifetime under extreme abrasive end-use conditions, but alsoprovides desirable high burst strength under the high temperatureconditions contemplated herein. Preferably, the polyolefin layer has athickness of about 3.2 to about 102 mm (about 0.125 to about 4 inches),or about 6.3 to about 76 mm (about 0.25 to about 3 inches), or about 13to about 51 mm (about 0.5 to about 2 inches) to provide greater levelsof end-use lifetime, burst strength and temperature resistance.

The polyolefin pipe may have any dimensions (including outside diameter,inside diameter and length) required to meet the end-use needs. Forexample but not limitation, the polyolefin pipe preferably has an outerdiameter (OD) of about 2.54 to about 254 cm (about 1 to about 100inches), more preferably, about 25.4 to about 152 cm (about 10 to about60 inches) and most preferably, about 51 to about 102 cm (about 20 toabout 40 inches). For example but not limitation the polyolefin pipepreferably has a length of about 1.5 to about 12.2 m (about 5 to about40 feet), more preferably about 3.1 to about 9.1 m (about 10 to about 30feet) and most preferably about 5.5 to about 6.7 m (about 18 to 22feet), providing a convenient length for storage, transport, handlingand installation.

The polyolefin pipe may be produced by any suitable process. Forexample, the polyolefin pipe may be formed by melt extrusion, meltcoextrusion, slush molding, rotomolding, rotational molding or any otherprocedures known in the art. For example, the polyolefin pipe may beproduced by rotational or slush molding processes. The polyolefincomposition may be in the form of powder, microbeads or pellets for usein rotational molding processes. Methods for rotational molding of pipesare known (U.S. Pat. No. 4,115,508; U.S. Pat. No. 4,668,461; andZA9607413). For example, ZA9607413 discloses wear-resistant compositepipe linings produced through rotational molding a mixture of apolymeric material with an abrasion-resistant particulate material.Methods for rotational molding with polymer powders are known (U.S. Pat.Nos. 3,784,668; 3,876,613; 3,891,597; 3,974,114; 4,029,729; 4,877,562;5,366,675; 5,367,025; and 5,759,472). U.S. Pat. No. 3,974,114 disclosesrotational molding of articles with poly(ethylene-co-acrylic acid)copolymer powders. Methods for rotational molding with polymermicrobeads are known (U.S. Pat. No. 5,886,068; EP1422059; andEP1736502). U.S. Pat. No. 5,886,068 discloses rotational moldingprocesses using blends of micropellets. Methods for rotational moldingwith polymer pellets are known (U.S. Pat. Nos. 4,032,600; 4,185,067;5,232,644; and EP0778088). Methods for slush molding with polymerpowders are known (U.S. Pat. No. 6,218,474 and EP1169390).

Preferably, the polyolefin pipes are formed by melt extrusion andcoextrusion processes that are particularly preferred processes forformation of “endless” products. Methods for extruding polymers in theform of pipe are known (U.S. Pat. Nos. 2,502,638; 3,538,209; 3,561,493;3,755,168; 3,871,807; 3,907,961; 3,936,417; 4,069,001; 4,123,487;4,125,585; 4,196,464; 4,203,880; 4,301,060; 4,377,545; 4,402,658;4,465,449; 4,663,107; 4,888,148; 5,028,376; 5,089,204; 5,514,312;5,518,036; 5,643,526; 5,842,505; 5,976,298; 6,174,981; 6,241,840;6,418,732; 6,469,079; 6,787,207; US20050167892; US20070117932;EP0222199; EP1574772; WO95/07428; WO2000/018562; WO2006/090016; andWO2006/134228). The molten polymer is forced through an annular die anda mandrel to provide the hollow circular profile of the pipe with theinner pipe diameter controlled by the size of the mandrel. The diameterof the pipe may also be controlled through the application of airpressure inside the pipe. The outer diameter may be controlled withexternal sizing dies or sleeves. The pipe is cooled to form the finalshape. Multilayer pipe is produced similarly using a multilayer annulardie that is fed by two or more extruders.

Multilayer Polyolefin Pipe.

The article may be in the form of a multilayer pipe comprising aninnermost layer of the polyolefin composition and an outside layercomprising a polymeric material. Examples of preferred polymericmaterials for the outside layer include poly(meth)acrylics,polyacrylates, urethane modified polyacrylics, polyester modifiedpolyacrylics, polystyrenes, polyolefins, polyethylenes (such as highdensity polyethylene, low density polyethylene, linear low densitypolyethylene, ultralow density polyethylene), polypropylenes,polyurethanes, polyureas, epoxy resins, polyesters (such aspoly(ethylene terephthalate), poly(1,3-propyl terephthalate),poly(1,4-butylene terephthalate), PETG,poly(ethylene-co-1,4-cyclohexanedimethanol terephthalate)), alkydresins, polyamides (such as nylons, nylon 6, nylon 46, nylon 66, nylon612), polyamideimides, polyvinyls, phenoxy resins, amino resins,melamines, chlorine-containing resins, chlorinated polyethers,fluorine-containing resins, polyvinyl acetals, polyvinyl formals,poly(vinyl butyrate)s, polyacetylenes, polyethers, silicone resins, ABSresins, polysulfones, polyamine sulfones, polyether sulfones,polyphenylene sulfones, polyvinyl chlorides, polyvinylidene chlorides,polyvinyl acetates, polyvinyl alcohols, polyvinyl carbazoles, butyrals,polyphenylene oxides, polypyrroles, polyparaphenylenes,ultraviolet-curing resins, cellulose derivatives, diethylene glycolbis-allyl carbonate poly-4-methylpentene, polytetrafluoroethylene,polytrifluoroethylene, polyvinylidene fluoride,poly(ethylene-co-glycidylmethacrylate), poly(ethylene-co-methyl(meth)acrylate-co-glycidyl acrylate), poly(ethylene-co-n-butylacrylate-co-glycidyl acrylate), poly(ethylene-co-methyl acrylate),poly(ethylene-co-ethyl acrylate), poly(ethylene-co-butyl acrylate), acidcopolymers, acid terpolymers, poly(ethylene-co-(meth)acrylic acid),ionomers, ionomer terpolymers, metal salts ofpoly(ethylene-co-(meth)acrylic acid), poly((meth)acrylates),poly(ethylene-co-carbon monoxide), poly(ethylene-co-vinyl acetate),poly(ethylene-co-vinyl alcohol), polybutylene, poly(cyclic olefins),syndiotactic polystyrene, poly(4-hydroxystyrene), novalacs,poly(cresols), polycarbonates, poly(bisphenol A carbonate),polysulfides, poly(phenylene sulfide), poly(2,6-dimethylphenylenepreferred anhydrides and acids are selected from the group consisting ofacrylic acid, maleic anhydride and mixtures thereof. Preferably, thematerials to be grafted are selected from the preferred polymericmaterials recited above.

Fiber-Reinforced Polyolefin Pipe

The article may be in the form of a multilayer pipe comprising aninnermost layer having a thickness of about 0.001 to about 102 mm(0.00004 to 4 inches) comprising the polyolefin composition and an outerlayer comprising a fiber reinforcement and optionally a thermoset resin.

The article also may be in the form of a multilayer pipe comprising aninnermost layer having a thickness of about 0.001 to about 102 mm(0.00004 to 4 inches) comprising the polyolefin composition; anintermediate layer comprising a polymeric material; and an outer layercomprising fiber reinforcement and optionally thermoset resin.

The fiber reinforcement may be a filament, warp yarn, tape,unidirectional sheet, mat, cloth, knitted cloth, paper, non-woven fabricor woven fabric, or mixtures thereof. The fiber preferably comprises ahigh strength fiber such as fiberglass, continuous glass fiber,polyaramide fiber, aramid fiber, graphite, carbon fiber, silica, quartz,ceramic, silicon carbide, boron, alumina, alumina-silica, polyethylene,ultrahigh molecular weight polyethylene, polyimide, liquid crystalpolymers, polypropylene, polyester, polyamide and the like, and ispreferably about 3 to about 30 microns thick.

The fiber may be impregnated with a resin (“prepreg”), such asthermoplastic or preferably thermoset resins. Suitable resins forimpregnating the fiber layers include polyester, aromatic, aliphatic,cycloaliphatic or anhydride epoxy resins, vinylester, vinyl, acrylic,modified acrylic, urethane, phenolic, polyimide, bismaleimide, polyurea,siloxane-modified resins and the like and combinations thereof.

Fiber-reinforcement of thermoplastic pipe is known (U.S. Pat. Nos.4,081,302; 4,521,465; 5,629,062; 5,931,198; 6,737,134; 7,018,691;US2006/0151042; and WO2004/068016).

An adhesive may be applied to the polyolefin pipe and multilayerpolyolefin pipe prior to the application of the exterior reinforcementlayer and/or an adhesive may be applied to the reinforcement layer afterits application to the polyolefin pipe and multilayer polyolefin pipe.The exterior surface of the polyolefin pipe and multilayer polyolefinpipe may be heated to enhance the adhesion and/or embedding of thereinforcement layer. Suitable adhesives may include the impregnatedresins described above or any adhesive known in the art.

The fiber reinforcement may be applied to the polyolefin pipe andmultilayer polyolefin pipe by any method known in the art. For example,the fiber reinforcement may be applied using known filament windingprocesses through winding the fiber reinforcement onto the polyolefinpipe or multilayer polyolefin pipe or by wrapping the fiberreinforcement around the polyolefin pipe and multilayer polyolefin pipe.

Polyolefin-Lined Metal Pipe

An embodiment is an article in the form of a multilayer pipe comprisingan innermost layer having a thickness of about 0.001 to about 102 mm(0.00004 to 4 inches) comprising the polyolefin composition and an outerlayer comprising a metal, preferably in the form of a metal pipe.

The monolayer or multilayer polyolefin composition (such as in the formof pipe, film, or sheet) may be attached (adhered) to the metal outerlayer or not attached. The polyolefin or multilayer polyolefincompositions may be self-adhered to the metal layer or adhered throughthe use of an adhesion primer, coating, or layer. As used herein, whenthe polyolefin composition is said to be “self-adhered” to the metallayer, it is meant that there is no intermediate layer such as a primeror thin adhesive layer between the metal and the polyolefin ormultilayer polyolefin composition.

The pipe may comprise an innermost layer comprising the polyolefincomposition; an intermediate layer comprising a polymer material (suchas those polymeric materials described above); and an outer layercomprising metal.

The pipe may comprise an innermost layer comprising the polyolefincomposition; an intermediate layer comprising a polymer material; and anouter layer comprising metal, wherein the polyolefin layer is adhered tothe polymer material layer and the polymer material layer is adhered tothe metal layer.

The pipe may comprise an innermost layer comprising the polyolefincomposition; an intermediate layer comprising a polymer material; and anouter layer comprising metal, wherein the polyolefin layer isself-adhered to the polymer layer and the polymer layer is self-adheredto the metal layer.

The pipe may further comprise an intermediate layer comprising a fiberreinforcement material comprising a high strength fiber and optionally athermoset resin as described above.

Preferably, the metal pipe comprises carbon steel, steel, stainlesssteel, cast iron, galvanized steel, aluminum, copper and the like. Morepreferably the metal pipe comprises carbon steel to provide the physicalproperties required for the material conveying processes contemplatedherein.

The metal pipe may have any dimensions, including thickness, outerdiameter, inner diameter and length suitable for the intended use. Thepipe may have a hollow, substantially circular profile and the wallthickness may be generally uniform around the circumference of the pipe,or the pipe may have any profile and the wall thickness may vary aroundthe circumference of the pipe as desired. For example but notlimitation, the metal pipe may have a thickness of about 6.3 to about 51mm (about 0.25 to about 2 inches, about 9.5 to about 38 mm (about 0.375to about 1.5 inches) or about 13 to about 25.4 mm (about 0.5 to about 1inch). For example but not limitation, the metal pipe may have an outerdiameter (OD) of about 5.1 to about 254 cm (about 2 to about 100inches), about 25.4 to about 152 cm (about 10 to about 60 inches) orabout 51 to about 102 cm (about 20 to about 40 inches). For example butnot limitation the metal pipe may have a length of about 1.5 to about12.2 m (about 5 to about 40 feet), about 3.1 to about 9.1 m (about 10 toabout 30 feet) or about 5.5 to about 6.7 m (about 18 to 22 feet) toprovide a convenient length for storage, transport, handling andinstallation.

The polyolefin-lined metal pipe may be produced by any known method. Forexample, the polyolefin pipe and multilayer polyolefin pipe may serve asa liner for a metal pipe. Methods for lining a pipe with a polymericliner are known (U.S. Pat. Nos. 3,315,348; 3,429,954; 3,534,465;3,856,905; 3,959,424; 4,207,130; 4,394,202; 4,863,365; 4,985,196;4,998,871; 5,072,622; 5,320,388; 5,374,174; 5,395,472; 5,551,484;5,810,053; 5,861,116; 6,058,978; 6,067,844; 6,240,612; 6,723,266;2006/0093436; 2006/0108016; US2006/0124188; US2006/0151042; andEP0848659).

The inside surface of the metal pipe may be pretreated to provideenhanced adhesion and stability. Such treatments include descaling bysand-, metal grit- or shot-blasting, acid etching, cleaning the metalsurface through solvent or chemical washes to remove grease and/or oxidelayers, and the application of adhesion primers, coatings, or layers.

A polyolefin-lined metal pipe may be prepared by pulling or inserting apreformed polyolefin pipe or multilayer polyolefin pipe into a preformedmetal pipe wherein the outer diameter of the polyolefin pipe is lessthan the interior diameter of the metal pipe. This method to produce apolyolefin-lined metal pipe includes the following embodiments.

The method comprises (i) pulling or inserting a pre-formed polyolefinpipe or multilayer polyolefin pipe into the metal pipe; (ii) heating thepolyolefin-lined metal pipe above the softening point of the polyolefincomposition; and (iii) allowing the metal pipe to cool.

The method comprises (i) heating a metal pipe above the softening pointof the polyolefin composition; (ii) pulling or inserting a pre-formedpolyolefin pipe or multilayer polyolefin pipe into the heated metalpipe; and (iii) allowing the metal pipe to cool.

The method comprises (i) coating a layer of an adhesive or adhesionprimer onto the outside surface of the polyolefin pipe or multilayerpolyolefin pipe; and (ii) pulling or inserting the adhesive-treatedpolyolefin pipe or multilayer polyolefin pipe into the metal pipe.

The method comprises (i) coating a layer of an adhesive or adhesionprimer onto the inside surface of the metal pipe; and (ii) pulling orinserting the polyolefin pipe or multilayer polyolefin pipe into theadhesive-treated metal pipe.

The method comprises (i) coating a layer of an adhesive or adhesionprimer onto the outside surface of the polyolefin pipe or multilayerpolyolefin pipe; (ii) pulling or inserting the adhesive-treatedpolyolefin pipe or multilayer polyolefin pipe into the metal pipe; (ii)heating the metal pipe above the softening point of the polyolefincomposition; and (iv) allowing the metal pipe to cool.

The method comprises (i) coating a layer of an adhesive or adhesionprimer onto the inside surface of the metal pipe; (ii) pulling orinserting the polyolefin pipe or multilayer polyolefin pipe into theadhesive-treated metal pipe; (ii) heating the metal pipe above thesoftening point of the polyolefin composition; and (iv) allowing themetal pipe to cool.

The method comprises (i) coating a layer of an adhesive or adhesionprimer onto the outside surface of the polyolefin pipe or multilayerpolyolefin pipe; (ii) heating a metal pipe above the softening point ofthe polyolefin composition; (iii) pulling or inserting theadhesive-treated polyolefin pipe or multilayer polyolefin pipe into theheated metal pipe; and (iv) allowing the metal pipe to cool.

The method comprises (i) coating a layer of an adhesive or adhesionprimer onto the inside surface of the metal pipe; (ii) heating theadhesively-treated metal pipe above the softening point of thepolyolefin composition; (iii) pulling or inserting the polyolefin pipeor multilayer polyolefin pipe into the heated metal pipe; and (iv)allowing the metal pipe to cool.

In a specific embodiment, the method for adhering the polyolefin pipe ormultilayer polyolefin pipe to the metal pipe comprises (a) descaling andcleaning the interior surface of the metal pipe; (b) heating the metalpipe to a temperature of about 150 to about 400° C., preferably about150 to about 300° C. and most preferably about 175 to about 225° C.; (c)pulling or inserting the polyolefin liner (pipe) or polyolefinmultilayer liner (pipe) into the hot metal pipe; and (d) allowing thepolyolefin-lined metal pipe to cool to ambient conditions.

For example, preparing a polyolefin lined metal pipe with a self-adheredpolyolefin liner (pipe) includes descaling the interior of the metalpipe, followed by degreasing and cleaning The metal pipe is then heated,as in an oven, a furnace, a gas ring burner, electrical resistiveheating elements, radiant heaters, induction heating, high frequencyelectrical heaters and the like, and the heating may be discontinuedthroughout the remainder of the process or the metal pipe may becontinuously heated, as through induction heating, throughout theprocess. The heating expands the metal pipe. A polyolefin liner (pipe)or polyolefin multilayer liner (pipe) is pulled or inserted into the hotmetal pipe. The polyolefin or multilayer polyolefin liner preferably hasan outside diameter (OD) that is no greater than about 0.1 inch (2.5 mm)less than the inside diameter (ID) of the unheated metal pipe, morepreferably an OD no greater than about 0.05 inch (1.3 mm) less than theID, even more preferably, an OD no greater than about 0.025 inch (0.64mm) less than the ID. Most preferably, the polyolefin and multilayerpolyolefin liner OD is about equivalent to the ID of the unheated metalpipe. As the heated metal pipe-polyolefin liner structure cools, themetal pipe reduces in diameter and makes intimate contact with theoutside surface of the polyolefin liner, causing it to soften andself-adhere to the inside surface of the metal pipe. Alternatively, thepolyolefin liner (pipe) or multilayer polyolefin liner (pipe) may beinserted into the metal pipe prior to heating.

If desired, prior to heating the metal pipe and inserting the polyolefinor multilayer polyolefin liner (pipe), an adhesive primer, coating orlayer may be applied to the interior surface of the metal pipe, theexterior surface of the polyolefin or multilayer polyolefin liner, orboth, in the form of a solution or solid to provide enhanced interlayeradhesion.

A method to produce a polyolefin-lined metal pipe comprises laying up apre-formed polyolefin film or sheet or multilayer polyolefin film orsheet into a preformed metal pipe. This method to produce apolyolefin-lined metal pipe includes the following embodiments.

The method comprises (i) laying up the interior of a metal pipe withpolyolefin film or sheet or multilayer polyolefin film or sheet; (ii)heating a metal pipe above the softening point of the polyolefincomposition; and (iii) allowing the metal pipe to cool.

The method comprises (i) coating a layer of an adhesive or adhesionprimer onto the outside surface of the polyolefin film or sheet ormultilayer polyolefin film or sheet; and (ii) laying up the interior ofa metal pipe with polyolefin film or sheet or multilayer polyolefin filmor sheet.

The method comprises (i) coating a layer of an adhesive or adhesionprimer onto the inside surface of the metal pipe; and (ii) laying up theinterior of a metal pipe with polyolefin film or sheet or multilayerpolyolefin film or sheet.

The method comprises (i) coating a layer of an adhesive or adhesionprimer onto the outside surface of the polyolefin film or sheet ormultilayer polyolefin film or sheet; (ii) laying up the interior of ametal pipe with polyolefin film or sheet or multilayer polyolefin filmor sheet; (iii) heating a metal pipe above the softening point of thepolyolefin composition; and (iv) allowing the metal pipe to cool.

The polyolefin film or sheet and the multilayer polyolefin film or sheetmay be produced by any art method. Preferably the film or sheet isproduced through melt processes, such as extrusion blown film processes,extrusion film or sheet melt casting processes, sheet profile extrusionprocesses, calendar processes and the like. The films and sheets mayundergo secondary formation processes, such as the plying together ofpreformed sheets to produce thicker sheets through known calendaringprocesses.

An example method for preparing polyolefin lined metal pipe with aself-adhered polyolefin sheet includes descaling the interior of themetal pipe, followed by degreasing and cleaning. The interior of themetal pipe is then covered with the polyolefin sheet, preferably withthe sheet overlapping onto itself 0.5 to 4 inches to form a seam. Theseam may be heat fused or the excess sheet may be trimmed and the sheetends may be heat fused, as desired. The metal pipe is then heated, asdescribed above, to the temperature range of about 150 to about 400° C.,preferably to the temperature range of about 150 to about 300° C. andmost preferably to the temperature range of about 175 to about 225° C.As the heated metal pipe-polyolefin sheet structure cools, the metalpipe makes intimate contact with the outside surface of the polyolefinsheet, causing it to soften and self-adhere to the inside surface of themetal pipe.

If desired, prior to heating the metal pipe and inserting the polyolefinor multilayer polyolefin film or sheet, an adhesive primer, coating orlayer may be applied to the interior surface of the metal pipe, theexterior surface of the polyolefin or multilayer polyolefin film orsheet or both, in the form of a solution or solid to provide enhancedinterlayer adhesion.

The polyolefin-lined metal pipe may be produced by powder coatingprocesses. Methods for coating the inner or outer surfaces of a pipewith polymeric powder coatings are known (U.S. Pat. Nos. 3,004,861;3,016,875; 3,063,860; 3,074,808; 3,138,483; 3,186,860; 3,207,618;3,230,105; 3,245,824; 3,307,996; 3,488,206; 3,532,531; 3,974,306;3,982,050; 4,007,298; 4,481,239; and EP778088). For example, U.S. Pat.No. 4,407,893 discloses powder coating processes to produceabrasion-resistant pipes with 0.04-inch thick coatings of sand-filledblends comprising polyethylenes and ionomers.

The polyolefin composition may be produced in the form of a powder byany known method. Methods for producing polymer powders (comprising acidcopolymers and ionomers), and powder coating compositions are known(U.S. Pat. Nos. 3,933,954; 3,959,539; 4,056,653; 4,237,037; 5,344,883;6,107,412; 6,132,883; 6,284,311; 6,544,596; 6,680,082; and EP1169390).

Preferably, the polyolefin composition is cryogenically (for example,with liquid nitrogen as the cooling medium) ground into a powder.Physically grinding the grafted polyolefin composition createsirregularly shaped particles of size and shape suitable for achievingconstant flow through the application equipment. Preferably, the graftedpolyolefin composition powder has a particle size or average particlesize of about 20 to about 500 micrometers. To obtain the suitableparticle size, the grinding step may include a sieving or classificationstep to eliminate large- and fine-sized particles. For fluid bed coatingprocesses, the preferred particle size is of about 75 to about 350micrometers.

A method to produce a polyolefin-lined metal pipe comprises (i) heatinga metal pipe above the softening point of a polyolefin composition; (ii)fluidizing the polyolefin composition in the form of a powder; (iii)supplying the fluidized polyolefin powder to the inside of the heatedmetal pipe until the desired polyolefin thickness is achieved; and (iv)allowing the metal pipe to cool.

The heated metal pipe may be in a vertical orientation or a horizontalorientation during step (iii). The heated metal pipe may be rotatedduring step (iii). For example, the heated metal pipe may be rotated ata rate to force the polyolefin powder to the inside diameter of themetal pipe during step (iii).

The powder coating process comprises heating the metal pipe to atemperature above the softening point of the polyolefin composition andsupplying a fluidized powder of the polyolefin composition into theheated pipe for a time sufficient to provide the desired polyolefincoating thickness. The metal pipe is preferably heated to thetemperature range of about 150 to about 400° C., preferably about 200 toabout 350° C. and most preferably about 250 to about 300° C. The metalpipe may be heated as described above and the heating may bediscontinued throughout the remainder of the process or the metal pipemay be continuously heated throughout the process. Portions of the pipemay be selectively heated. For example, in a fluidized bed method (seebelow) the metal pipe may be incrementally heated from the top to thebottom to cause the coating to form sequentially from the top to thebottom. Conversely, the metal pipe may be heated from the bottom to thetop.

The polyolefin coating may be self-adhered to the metal pipe or theinterior surface of the metal pipe may be treated with adhesion primers,coatings and layers. The use of adhesion promoting primers and couplingagents for pipe powder coatings is known (U.S. Pat. Nos. 3,016,875;4,048,355; and 4,481,239).

Pipe powder coating methods may include descaling, degreasing andcleaning the interior of the metal pipe, as described above. Theportions of the pipe that are not desired to be coated, for example themetal pipe ends which are meant to be joined together to form thepipeline, may be masked. If desired, prior to feeding the powder, anadhesive primer, coating or layer may be applied to the interior surfaceof the metal pipe in the form of a solution or solid (powder) to provideenhanced interlayer adhesion. The metal pipe is then heated as describedabove. The metal pipe temperature may be varied as desired during thecoating operation. Preferably, the heated metal pipe may be rotatedabout its cylindrical axis at a rate of about 1 to about 300 rpm, morepreferably about 10 to about 80 rpm. The metal pipe may be rotatedslowly to provide good, even coverage of the powder coating or may berotated fast enough to force the powder to the interior surface of thepipe. The metal pipe may be in a vertical orientation or preferably in ahorizontal orientation. If a multilayer coating is desired, differentpolymeric composition powders may be fed sequentially to provide thedifferent coating layers at the thickness desired. At any stage of theprocess, abrasion-resistant particles, such as described above asfillers, may be fed into the interior of the metal pipe, eitherindividually or in combination with the powder. For example, theabrasion-resistant particles may be overcoated onto the hot coatingwhile it is still soft and tacky so that the particles adhere to theinterior surface of the coating. The coated metal pipe is then allowedto cool to ambient temperatures. If desired, any coating surfaceroughness may be smoothed through a post-coating operation, such as byhot gas, flame or oven post-treatments.

In a fluidized bed method, the powder is fed with pressurized gas, suchas compressed air, nitrogen or argon, from a fluidized bed of the powderinto the interior of the hot metal pipe. Alternatively, the hot metalpipe may be placed above the fluidized bed and the fluidized bed allowedto expand into the interior of the hot metal pipe to be coated. As thepowder contacts the heated interior surface of the metal pipe, thematerial coalesces and flows to form a continuous, fused coating. Thepowder is fed from the fluidized bed until a continuous, uniform coatingof the desired thickness is achieved.

In a spray coating method, a spray nozzle, preferably with a deflectordisc to force the powder radially out onto the metal pipe interiorsurface, supported on an extensible boom, is inserted down thecenterline of the metal pipe interior. The powder may be fed withpressurized gas, such as compressed air, nitrogen or argon, from afluidized bed of the powder. Alternatively, the powder may be deliveredfrom a bin to a vibrating feeder into a hopper and then conveyed to thespray nozzle with a pressurized gas. During the coating operation, thespray nozzle, the metal pipe or both may be moved to ensure uniformcoating over the interior surface of the pipe. Multiple coats may beapplied to provide the desired coating thicknesses.

The polyolefin composition powder may be applied to the inside metalpipe surface through electrostatic spraying processes. For electrostaticspraying applications, the preferred particle size is about 20 to about120 micrometers. Preferably, the metal pipe is preheated above thesoftening point of the polyolefin composition as described above. Inelectrostatic spraying processes, the polyolefin powder is fed out of areservoir, such as a fluidized bed, to a spray gun by air pressure. Ahigh voltage, low amperage electrostatic charge is applied to thepolyolefin powder by a transfer of electrons from the spray gun to thepowder. The charged powder is sprayed onto the cleaned inside surface ofthe preheated, grounded metal pipe to form the polyolefin coating.Several passes may be required to build up to the desired thickness ofthe coating.

The polyolefin composition coating may be applied to the metal pipe bythermal spraying processes, such as flame (combustion) spraying, twowire arc spraying, plasma spraying, cold spraying and high velocityoxy-fuel spraying. Preferably, the thermal spraying process is a flamespraying process. The polyolefin composition may be in the form of awire or a rod to serve as a feedstock for flame spraying processes, orit is a powder with a preferred particle size of about 1 to about 50micrometers. The polyolefin powder is fed to the flame spraying gun in astream of an inert gas (such as argon or nitrogen) and fed into a flameof a fuel gas (such as acetylene or propane) and oxygen. The polyolefinpowder is melted in the flame and is sprayed onto the cleaned insidesurface of the preheated metal pipe with the help of a second outerannular gas nozzle of compressed air to form the polyolefin coating.Several passes may be required to build up to the desired thickness ofthe polyolefin coating. Alternatively, the polyolefin powder may be fedto the flame spray gun using a venturi effect sustained by the fuel gasflow.

The polyolefin compositions may be too soft for the formation ofsuitable powder to support powder-based processes. Even if suitablepowder were produced from the polyolefin compositions, the powder maytend to mass (stick together). Powder-based processes to produce thepipe are therefore not preferred.

The polyolefin-lined metal pipe may be produced by processes similar tothe above mentioned rotational or slush molding processes. Thepolyolefin composition may be in the form of powder, microbeads orpellets. The coating process comprises heating the metal pipe to atemperature above the softening point of the polyolefin composition,horizontally rotating the pipe and supplying the polyolefin compositioninto the heated pipe for a time sufficient to provide the desiredpolyolefin coating thickness. The metal pipe may be preheated (such asin an oven), may be constantly heated during the process or both. Thepolyolefin composition may be fed all at once (batchwise) orcontinuously to the rotating heated metal pipe. After an even coating ofthe desired thickness of the polyolefin composition is applied to theinner surface of the metal pipe, the pipe is cooled.

The pipes described herein provide high abrasion-resistance andcorrosion resistance for the conveyance of solids and slurries such asfound in the agriculture, food and mining industries. The polyolefinlayer in the pipes provides very long lifetime, especially desirable forthose industries that require long service lifetime due to the greatmaintenance and replacement complexity and cost. For example, oil slurrymining operations require kilometers of slurry pipelines in extremeenvironments, such as northern Alberta, Canada, so extended pipelifetime is very desirable.

A method for transporting an abrasive material comprises obtaining apipe- or tube-formed article as described above; preparing an abrasivematerial composition suitable for flowing through the article; flowingthe abrasive material composition into one end of the pipe- ortube-formed article and receiving the abrasive material composition outof the other end of pipe- or tube-formed article. The abrasive materialcomposition may be moved through the pipe by any motive force such asgravity and/or the action of a pump such as a jet pump.

The abrasive material composition may be a slurry, such as a combinationof water, oil, air, emulsified materials, particulates, solids and/orthe like. A slurry of note is oil sand slurry. In some cases, theabrasive material, such as oil sand slurry, may be at a temperature ofabout 30° C. or greater, of about 40° C. or greater, or about 50° C. orgreater. Oil sand slurries may be prepared as described in, for example,US2006/0249431. The oil sand slurry may be optionally conditioned bytransport through the pipe- or tube-formed article, such conditioningcomprising for example lump digestion, bitumen liberation, coalescenceand/or aeration. Pumping the slurry through a pipeline over a certainminimum distance (such as at least one kilometer, preferably at least 2kilometers), allows for conditioning the slurry. This is due to theincreased time (such as 10 minutes or greater) in the pipeline, whichallows transport through the pipeline to replace conditioning of the oilsand in a batch tumbler. In a low energy extraction process, the minedoil sand is mixed with water in predetermined proportions near the minesite to produce a slurry containing entrained air with density of 1.4 to1.65 g/cc and preferably a temperature of 20-40° C. Pumping the slurrythrough a pipeline having a plurality of pumps spaced along its length,preferably adding air to the slurry as it moves through the pipeline,conditions the slurry for further operations to extract bitumen from theslurry.

Examples

The following Examples are intended to be illustrative of the invention,and are not intended in any way to limit its scope.

Methods

Melt Index (MI) was measured by ASTM D1238 at 190° C. using a 2160 g,unless indicated otherwise. A similar ISO test is ISO 1133. Shore Ahardness is measured according to ASTM D2240, ISO 868.

Materials Used

-   PO1: high density polyethylene (density 0.960 g/cc) with MI of 2    g/10 min.-   PO2: poly(ethylene-co-hexene) (density 0.918 g/cc) with MI of 2 g/10    min.-   PO3: poly(ethylene-co-hexene) (density 0.918 g/cc) with MI of 2.7    g/10 min.-   PO4: an EPDM (density of 0.882 g/cc) with MI of 23 g/10 min.-   PO5: poly(ethylene-co-butene) (density 0.873 g/cc) with MI of 3.7    g/10 min.-   PO6: poly(ethylene-co-octene) (density 0.863 g/cc) with MI of 1.6    g/10 min.-   ACR: poly(ethylene-co-n-butylacrylate-co-methacrylic acid)    containing 23 wt % n-butylacrylate and 9 wt % methacrylic acid with    MI of 5 g/10 min.-   EO: ametallocene-catalyzed ethylene-octene copolymer plastomer sold    as EXACT 5361 by ExxonMobil Chemical Company, Houston, Tex.    (ExxonMobil).-   EP1: a metallocene-catalyzed ethylene-propylene copolymer, sold as    VISTALON EPM 722 by ExxonMobil.-   EP2: a metallocene-catalyzed ethylene-propylene copolymer, sold as    VISTAMAXX VM1100 by ExxonMobil.-   EP3: EP2 grafted with 2 wt % maleic anhydride.-   EPDM: a metallocene-catalyzed ethylene-propylene-diene copolymer,    sold as VISTALON 5601 by ExxonMobil.-   HDPE1: a high density poly(ethylene).-   HDPE2: a high density poly(ethylene) grafted with 1.5 wt % maleic    anhydride.-   S: a styrene block copolymer sold as KRATON G7705-1 by Kraton    Polymers, Houston, Tex. (Kraton).-   SBS: a styrene-butadiene-styrene block copolymer with MI of 3 g/10    min at 200° C./5 kg, sold as KRATON D1153E (Kraton).-   SEBS 1: a styrene-ethylene/styrene block copolymer with MI of 5 g/10    min at 230° C./5 kg, sold as KRATON G1652M (Kraton).-   SEBS 2: a styrene-ethylene/styrene block copolymer grafted with 1.7    wt % maleic anhydride, sold as KRATON FG1901X (Kraton).-   SEBS 3: a styrene-ethylene/styrene block copolymer grafted with 1 wt    % maleic anhydride, sold as KRATON FG1924X (Kraton).-   SIS: a styrene-isoprene-styrene block copolymer with MI of 3 g/10    min at 200° C./5 kg, sold as KRATON D111K (Kraton).

Comparative Example CE 1 and Examples 1-7

Abrasion resistance is assessed according to the following procedure.Wear test coupons are cut from injection molded plaques of the lowdensity polyolefins PO2 to PO6 and for comparison, high density PO1. Thewear test coupons are 50 mm by 50 mm by 6.35 mm thick. The wear testcoupons are dried in a vacuum oven (20 inches Hg) at a temperature of35° C. until the weight loss is less than 1 mg/day and then weighed. Thewear test coupons are then mounted in a test chamber and a 10 wt %aqueous sand (AFS50-70 test sand) slurry at room temperature (20-25° C.)is impinged on the wear test coupon through a slurry jet nozzlepositioned 100 mm from its surface with a diameter of 4 mm at a slurryjet rate of 15-16 meters/second with a slurry jet angle of 90° relativeto the surface plane for 2 hours. Example 6 is performed with the 10 wt% aqueous sand slurry at a temperature of 30° C. Example 7 is performedwith the 10 wt % aqueous sand slurry at a temperature of 20° C. The weartest coupons are then removed and dried in a vacuum oven (20 inches Hg)at room temperature for at least 15 hours and then reweighed. The weightloss in grams and % indicates the amount of wear

TABLE 1 Example CE 1 1 2 3 4 5 6 7 Material PO1 PO2 PO3 PO4 PO5 PO6 PO5PO6

Examples 8-16

The polyolefin pipes summarized in Table 2 are made from the materialslisted by conventional pipe extrusion and sizing methods with meltextrusion temperatures of about 150° C. to about 225° C. The pipes arecut into 20 foot lengths. “OD”=outer diameter.

TABLE 2 Monolayer Polyolefin Pipes OD Thickness Example Material(inches) (inches) 8 PO5 20 0.5 9 PO6 24 1.0 10 PO5 28 2.0 11 PO2 22 0.3812 PO3 26 0.75 13 PO6 32 1.5 14 PO4 26 0.4 15 PO5 30 1.0 16 PO6 34 1.8

Examples 17-22

The polyolefin bilayer pipes summarized in Table 3 are made from thematerials in Table 3 by conventional multilayer pipe extrusion andsizing methods with melt extrusion temperatures of about 150° C. toabout 225° C. The pipes are cut into 20 foot lengths.

TABLE 3 Inner Layer Outer Layer Thickness Thickness Example Material(inch) Material (inch) OD (in) 17 PO5 0.5 ACR 0.25 20 18 PO3 1.0 EPDM0.4 24 19 PO5 2.0 HDPE 1 0.5 28 20 PO6 0.38 SEBS 2 0.2 22 21 PO4 0.75SEBS 3 0.3 26 22 PO6 1.5 HDPE 2 0.5 32

Examples 23-31

Multilayer polyolefin pipes are made from the materials summarized inTable 4 by conventional multilayer pipe extrusion and sizing methodswith melt extrusion temperatures of about 150° C. to about 225° C. Thetielayer is approximately 1-2 mils thick (0.026-0.051 mm) and ispositioned between the inner layer and outer layer to provide adhesion.All Examples also have a tielayer on the outside surface of the outerlayer, e.g.; the structure of the pipe is tielayer/outerlayer/tielayer/inner layer. The pipes are cut into 20-foot lengths.

TABLE 4 Inner Layer Outer Layer Exam- Thickness Tie Layer Thickness pleMaterial (inch) Material Material (inch) OD (in) 23 PO5 0.5 EP 3 EO 0.2520 24 PO3 1.0 EP 3 EP 1 0.4 24 25 PO6 2.0 EP 3 EP 2 0.5 28 26 PO4 0.38EP 3 EPDM 0.2 22 27 PO5 0.75 HDPE 2 HDPE 1 0.3 26 28 PO5 1.5 SEBS 2 S0.5 32 29 PO6 0.45 SEBS 3 SBS 0.2 26 30 PO6 1.0 SEBS 2 SEBS 1 0.1 30 31PO4 1.8 SEBS 2 SIS 0.3 34

Examples 32-38

The polyolefin pipe-lined carbon steel pipes summarized in Table 5 aremade by inserting the polyolefin pipes listed into 20-foot lengths ofcarbon steel pipes with 0.75-inch wall thickness with the inner diameter(ID) listed. Prior to lining the pipe, the interior surface of thecarbon steel pipe is sandblasted and degreased.

TABLE 5 Polyolefin Pipe Carbon Steel Pipe Example (Example) ID (inches)32 8 22 33 12 28 34 15 32 35 18 26 36 22 34 37 26 24 38 29 28

Examples 39-46

The polyolefin pipe-lined pipelines summarized in Table 6 are made bythermally fusing the ends (“butt fusion”) of the polyolefin pipes listedthrough conventional methods and inserting the polymeric pipes into thecarbon steel pipes with 0.75-inch wall thickness and the length and theinner diameter (ID) listed. Prior to lining the pipe, the interiorsurface of the carbon steel pipe is sandblasted and degreased.

TABLE 6 Polyolefin Pipe Carbon Steel Pipeline Example (Example) ID(inch) Length (km) 39 9 26 1 40 11 24 2 41 16 36 3 42 17 22 0.5 43 19 301.5 44 24 26 1 45 39 28 2 46 30 32 3

Examples 47-68

The polyolefin pipe-lined carbon steel pipes summarized in Table 7 aremade by heating 20 foot lengths of carbon steel pipes with 0.75-inchwall thickness and the inner diameter (ID) listed to 200° C.; insertingthe polyolefin pipes listed into the hot carbon steel pipes; andallowing the lined pipe to cool to ambient temperatures. Prior to liningthe pipe, the interior surface of the carbon steel pipe is sandblastedand degreased.

TABLE 7 Polyolefin Pipe Carbon Steel Pipe Example (Example) ID (inches)47 8 20 48 9 24 49 10 28 50 11 22 51 12 26 52 13 32 53 14 26 54 15 30 5516 34 56 17 20 57 20 22 58 21 26 59 22 32 60 23 20 61 24 24 62 25 28 6326 22 64 27 26 65 28 32 66 29 26 67 30 30 68 31 34

Preparative Examples PE1-PE9

Polyolefin sheets with a thickness of 0.125 inch and a width of 9 feetare made from the materials summarized in Table 8 by conventional sheetextrusion methods with melt extrusion temperatures of about 150° C. toabout 225° C. The sheets are plied together to provide the describedthickness by conventional calendering processes.

TABLE 8 Polyolefin Sheets Preparative Example Material Sheet (inches)PE1 PO5 0.5 PE2 PO5 1.0 PE3 PO5 2.0 PE4 PO6 0.25 PE5 PO3 0.75 PE6 PO41.5 PE7 PO6 0.5 PE8 PO6 1.0 PE9 PO6 1.75

Examples 69-77

The polyolefin-lined carbon steel pipes summarized in Table 9 are madeby inserting the polyolefin sheets listed into 20-foot lengths of carbonsteel pipes with 0.75-inch wall thickness with the inner diameter (ID)listed. Prior to lining the pipe, the interior surface of the carbonsteel pipe is sandblasted and degreased. The polyolefin sheets are cutdown in size to fit the carbon steel pipe and the seam is butt welded bythermally fusing the ends (“butt fusion”). The polyolefin-lined carbonsteel pipe is heated to 200° C. while being rotated in the horizontalaxis, and then the lined pipe is cooled to ambient temperatures.

TABLE 9 Polyolefin Sheet Carbon Steel Pipe Example (Example) ID (inches)69 PE1 22 70 PE2 28 71 PE3 32 72 PE4 26 73 PE5 34 74 PE6 24 75 PE7 28 76PE8 20 77 PE9 30oxide), elastomers, rubbers, thermoplastic elastomers and the like andcopolymers thereof and mixtures thereof.

More preferably, the polymeric materials are selected from the groupconsisting of rubbers, elastomers, thermoplastic elastomers, acidterpolymers, ionomer terpolymers and the like and combinations thereof.Rubbers and elastomers are generally categorized as diene elastomers,saturated elastomers, thermoplastic elastomers and inorganic elastomers.Specific examples of rubbers and elastomers include natural rubber,polyisoprene, butyl rubber (copolymer of isobutylene and isoprene),polybutadiene, styrene butadiene (SBR, copolymer of polystyrene andpolybutadiene), nitrile rubber (copolymer of polybutadiene andacrylonitrile, also referred to as “buna N rubbers”), silicone RTV, FKMVITON (DuPont) (copolymer of vinylidene fluoride andhexafluoropropylene), SANTOPRENE (Advanced Elastomer Systems, LP, Akron,Ohio), fluorosilicone rubber, EPM and EPDM rubber (ethylene propylenerubber, a copolymer of polyethylene and polypropylene), polyurethanerubber, polyurea rubber, resilin, polyacrylic rubber (ABR),epichlorohydrin rubber (ECO), polysulfide rubber, chlorosulfonatedpolyethylene (CSM, HYPALON (DuPont)) and the like. Thermoplasticelastomers are generally categorized as styrenics (S-TPE), copolyesters(COPE), polyurethanes (TPU), polyamides (PEBA), polyolefin blends (TPO),polyolefin alloys (TPV), reactor TPO (R-TPO), polyolefin plastomers(POP), polyolefin elastomers (POE) and the like. Acid terpolymers aremade from α-olefins, α,β-ethylenically unsaturated carboxylic acids andpreferably about 10 to about 25 wt % other unsaturated comonomers (allas described above).

The polymer material layer may have any thickness. Preferably, thepolymer material layer is about 0.1 to about 102 mm (about 0.004 toabout 4 inches), or about 1 to about 25.4 mm (about 0.04 to about 1inch) or about 2.5 to about 12.7 mm (about 0.1 to about 0.5 inch) thick.

Tielayers may be included between any of the layers to enhance theadhesion between the layers. Any material may be used in tielayers, suchas anhydride- or acid-grafted materials. The preferred anhydrides andacids are α,β-ethylenically unsaturated carboxylic acid comonomersselected from the group consisting of acrylic acid, methacrylic acid,itaconic acid, maleic acid, maleic anhydride, fumaric acid, monomethylmaleic acid, and mixtures thereof. Most

1. A pipe- or tube-shaped article having an innermost layer wherein theinnermost layer has a thickness of about 0.001 to about 102 mm andcomprises a polyolefin; and the polyolefin comprises repeat unitsderived from ethylene and 5 to 50 wt %, based on the total weight of thepolyolefin, of an α-olefin having 3 to 20 carbons and has a density ofabout 0.92 g/cc (ASTM D-792) or less.
 2. The article of claim 1 whereinthe polyolefin has a density of about 0.90 g/cc or less.
 3. The articleof claim 2 wherein the polyolefin has a density of about 0.88 g/cc orless and the α-olefin contains from 3 to 10 carbons; and the α-olefinsare selected from the group consisting of propene, 1-butene,3-methyl-1-butene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene,1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene,3-cyclohexyl-1-propene, vinyl cyclohexane.
 4. The article of claim 3wherein the polyolefin has a density of about 0.84-0.88 g/cc andcomposition further comprises from about 0.1 wt % to about 80 wt % of anabrasion-resistant filler, based on the total weight of the polyolefincomposition.
 5. The article of claim 3 further comprising an outer layerhaving a thickness of about 0.1 to about 102 mm and comprising rubber,elastomer, thermoplastic elastomer, acid terpolymer, ionomer terpolymer,or mixtures of two or more thereof.
 6. The article of claim 5 furthercomprising an intermediate layer between the innermost layer and theouter layer and the intermediate layer comprises rubber, elastomer,thermoplastic elastomer, acid terpolymer, ionomer terpolymer, orcombinations of two or more thereof.
 7. The article of claim 1 furthercomprising an outer layer comprising a fiber reinforcement material; thefiber reinforcement material comprises a high strength fiber andoptionally a thermoset resin; and the high strength fiber is producedfrom fiberglass, continuous glass fiber, polyaramide fiber, aramidfiber, graphite, carbon fiber, silica, quartz, ceramic, silicon carbide,boron, alumina, alumina-silica, polyethylene, ultrahigh molecular weightpolyethylene, polyimide, liquid crystal polymers, polypropylene,polyester, or polyamide.
 8. The article of claim 7 further comprising anintermediate layer between the innermost layer and the outer layer andthe intermediate layer comprises rubber, elastomer, thermoplasticelastomer, acid terpolymer, ionomer terpolymer, or mixtures of two ormore thereof.
 9. The article of claim 7 wherein the high strength fiberis filament, warp yarn, unidirectional sheet, mat, cloth, knitted cloth,paper, non-woven fabric, woven fabric, or mixtures of two or morethereof.
 10. The article of claim 1 further comprising an outermostlayer.
 11. The article of claim 10 comprising an outermost layer whichcomprises carbon steel, steel, stainless steel, cast iron, galvanizedsteel, aluminum, or copper, or alloys of two or more thereof.
 12. Thearticle of claim 11 wherein the outermost layer comprises carbon steel.13. The article of claim 1 further comprising an outermost layer incontact with the innermost layer.
 14. The article of claim 13 comprisingan outermost layer, in contact with the innermost layer, comprisingcarbon steel, steel, stainless steel, cast iron, galvanized steel,aluminum, or copper, or alloys of two or more thereof.
 15. The articleof claim 14 wherein the innermost layer is in contact with the outermostlayer and the outermost layer comprises carbon steel.
 16. The article ofclaim 6 wherein the article further comprises an outermost layer incontact with the innermost layer and the outermost layer comprisescarbon steel.
 17. A method comprising laying up a pre-formed film orsheet into a preformed metal or plastic pipe to produce apolyolefin-lined metal or plastic pipe wherein the film or sheet ismonolayer or multilayer film or sheet and is produced from a polyolefin;and the pre-formed film or sheet is as recited in claim
 1. 18. Themethod of claim 17 further comprising heating the metal or plastic pipeabove the softening point of the polyolefin and allowing the metal orplastic pipe to cool to produce the polyolefin-lined metal or plasticpipe.
 19. A method comprising pulling or inserting an article into theinterior surface of a metal pipe to produce a pipe- or tube-shapedarticle comprising a polyolefin; wherein the pipe is the articlecharacterized in claim
 1. 20. The method of claim 19 further comprisingproducing an abrasive material; flowing the abrasive material into oneend of the pipe- or tube-shaped article; receiving the abrasive materialout of the other end of pipe- or tube-shaped article for transportingthe abrasive material thereby transporting the abrasive material.